CN111987831B

CN111987831B - Stator of electric machine

Info

Publication number: CN111987831B
Application number: CN202010440730.9A
Authority: CN
Inventors: J·斯托尔; R·格雷夫
Original assignee: Dr Ing HCF Porsche AG
Current assignee: Dr Ing HCF Porsche AG
Priority date: 2019-05-23
Filing date: 2020-05-22
Publication date: 2023-05-30
Anticipated expiration: 2040-05-22
Also published as: DE102019113789A1; CN111987831A; US11641141B2; US20200373800A1

Abstract

The invention relates to a stator (10) for an electric machine, comprising: a stator slice group (16) comprising stator slices; and at least one stator winding (15) comprising conductor bars (11-14) which are arranged in the grooves (17) of the stator packet (16) and which are fixed in the grooves (17) of the stator packet (16) by means of fixing means (22). In order to improve the stator (10), in particular in terms of its service life and/or its manufacturability, the fastening device (22) comprises a nonwoven material (20) in the recess (17) which can be impregnated with a cooling liquid (28).

Description

Stator of electric machine

Technical Field

The present invention relates to a stator of an electric machine, the stator having: a stator slice group, the stator slice group comprising stator slices; and at least one stator winding comprising conductor bars which are arranged in the grooves of the stator plate package and which are fixed in the grooves of the stator plate package by means of fixing means. Furthermore, the invention relates to a method for producing such a stator. The invention also relates to a method for cooling a stator winding of such a stator.

Background

From international published application WO 2014/088900A1 a stator of an electric machine is known, wherein the stator has a stator base body and at least one winding, wherein conductors of the winding are arranged in grooves of the base body, wherein groove bottom insulation manufactured from a first fabric, foil and a second fabric is arranged in the grooves. US 6,798,105B1 discloses a stator of an electric machine, wherein the stator has a stator base body and at least one winding, wherein conductors of the winding are arranged in grooves of the base body, wherein the conductors are assembled, for example, in a woven manner. From US 4.994,700 an electric machine with a stator is known, which has a stator base body and at least one winding, which comprises conductor bars, which are arranged in grooves of the base body and are each fixed in the grooves by means of spring elements with wave-shaped cross sections, which surround the conductor bars. From german published application DE 18 16 283, a device is known for fastening winding bars or coils in a recess of a core body of an electric machine, wherein the recess is closed by at least one closure extending over at least a part of the core length, wherein a recess space between the recess closure and the recess bottom, which is not filled with a winding, is filled by a tubular hollow body formed from an elastic and magnetic material, within which a certain controllable pressure is permanently generated by means of a pressure generator device connected to one end thereof, such that a certain radial pressure is permanently applied to the bars or coils of the winding. From german published application DE 32 41 410a1, a device for fastening a winding of an electric machine, which winding consists of individual coils and is inserted into a stator slot, is known, which device accordingly has a slot closure consisting of slot closure wedges, spring elements and spring supports. A method for producing an electrical insulation of a winding of an electric machine is known from european patent application EP 0 489 882B1, which winding has winding sections which are inserted with play into grooves of a rotor or stator, wherein a thermally expandable laminate is introduced between the groove surfaces and the winding sections, which laminate contains an elastically compressible substance formed from highly elastic fibers. From german published application DE 10 2015 216 840A1 a stator for an electric machine is known, which stator has: a sheet group having a groove extending in an axial direction of the stator; and rods forming an electrically conductive electrical winding of the stator, at least one of the rods being arranged in each of the grooves, wherein each rod is electrically insulated relative to the sheet set by a respective electrically insulating element, wherein the electrically insulating element is designed as a hose element, which is formed of thermoplastic and surrounds the rod.

Disclosure of Invention

The object of the present invention is to improve the prior art stator, in particular with regard to its service life and/or its manufacturability.

In the case of a stator of an electric machine, the stator has: a stator slice group, the stator slice group comprising stator slices; and at least one stator winding comprising conductor bars arranged in the grooves of the stator sheet set and fixed in the grooves of the stator sheet set by means of fixing means, the object being achieved by: the fastening means comprise a nonwoven material in the recess which can be impregnated with a cooling liquid. The nonwoven material is used on the one hand for the groove bottom insulation. This provides, inter alia, the following advantages: the impregnation of the stator winding may be omitted.

A preferred embodiment of the stator is characterized in that the non-woven material comprises a volume which increases with the reception of the cooling liquid, such that the conductor bars are fixed in the grooves by the non-woven material impregnated with the cooling liquid. This provides, inter alia, the following advantages: additional fixing elements for fixing the conductor bars in the grooves of the stator plate package can be dispensed with.

A further preferred embodiment of the stator is characterized in that the non-woven material surrounds the conductor bars in the groove. These conductor bars are for example simply wound with the nonwoven material. The end sections of the nonwoven material may be arranged in an overlapping manner.

Another preferred embodiment of the stator is characterized in that the grooves are lined with the nonwoven material. Thus, the desired function of the nonwoven material can be achieved in a simple manner.

A further preferred embodiment of the stator is characterized in that in the recess a pressure difference is applied to the nonwoven material impregnated with the cooling liquid, which pressure difference causes the cooling liquid to flow around the conductor bars fixed with the impregnated nonwoven material. Thus, direct cooling of the windings can be achieved in a simple manner.

In a method for producing the stator described above, the above object is alternatively or additionally achieved by: the conductor bars are wrapped with the nonwoven material. The end sections of the nonwoven material can be folded over one another, for example.

Alternatively or additionally, the groove may be lined with the nonwoven material.

A preferred embodiment of the method is characterized in that the nonwoven material is impregnated with the cooling liquid in the recess. The nonwoven material is advantageously impregnated with the cooling liquid in the recess, so that the conductor bars are fixed in the recess with the impregnated nonwoven material.

In a method for cooling a stator winding of a stator as described above, the above object is alternatively or additionally achieved by: a pressure difference is applied to the nonwoven material impregnated with the cooling liquid in order to cool the conductor bars directly with the cooling liquid. The nonwoven material advantageously performs a dual function. In one aspect, the non-woven material is used to stably secure the conductor bars in the groove. Furthermore, the nonwoven material enables direct cooling of the conductor bars in the grooves.

The invention also relates to a non-woven fabric material for the stator. The nonwoven material is individually operable.

Drawings

Further advantages, features and details of the invention emerge from the following description of different embodiments which follows with reference to the drawings. In the drawings:

FIG. 1 illustrates a conventional stator plate having a plurality of grooves in a top view;

FIG. 2 shows an enlarged view of part II-II of FIG. 1 with a recess;

fig. 3 shows a groove (as it is shown in fig. 2) with a stator winding surrounded by a non-woven material impregnated with a cooling liquid; and is also provided with

Fig. 4 shows the recess in fig. 3, wherein a pressure difference is applied to the nonwoven material impregnated with the cooling liquid in order to cool the stator winding directly in the recess.

Detailed Description

In fig. 1, a conventional stator plate 1 having a total of fifty-four grooves 2 is shown in a top view.

In fig. 2 an enlarged part II from fig. 1 is shown with a groove 5. The recess 5 has a substantially rectangular geometry 4 which is upwardly open in fig. 2.

Fig. 3 shows a simplified illustration of a stator 10 with conductor bars 11 to 14 of a stator winding 15. The stator windings 15 are arranged in the grooves 17 of the stator plate package 16. The groove bottom 18 of the groove 17 is arranged below fig. 3. Above fig. 3, the groove 17 is closed by a stator seal 19.

In the gap 21 between the conductor bars 11 to 14 and the stator plate group 16, a nonwoven material 20 is arranged in the groove 17. The non-woven material 20 completely surrounds the conductor bars 11 to 14 of the stator winding 15. The end sections of the nonwoven material 20 are folded over one another over fig. 3.

The non-woven material 20 is used to form a securing means 22 for securing the conductor bars 11 to 14 of the stator winding 15 in the grooves 17. To activate the fastening means 22, the nonwoven material 20 is impregnated with a cooling liquid, as indicated by arrow 23 in fig. 3.

The cooling liquid is, for example, a conventional cooling liquid, as it is used for directly cooling the stator windings. The supply of the cooling liquid causes the nonwoven material 20 to expand in the grooves 17 until the gaps 21 are completely filled with the nonwoven material 20.

Seen in fig. 4: the conductor bars 11 to 14 of the stator winding 15 are stably fixed in the grooves 17 by the nonwoven material 20 impregnated with the cooling liquid 28. Furthermore, indicated in fig. 4 by arrows 25 and 26: a pressure difference is applied to the nonwoven material 20 impregnated with the cooling liquid 28 in order to cool the conductor bars 11 to 14 of the stator winding 15 directly with the cooling liquid 28 in the grooves 17.

List of reference numerals

1. Stator plate

2. Groove

4. Geometry shape

5. Groove

10. Stator

11. Conductor bar

12. Conductor bar

13. Conductor bar

14. Conductor bar

15. Stator winding

16. Stator sheet set

17. Groove

18. Groove bottom

19. Stator seal

20. Nonwoven material

21. Gap of

22. Fixing device

23. Arrows

25. Arrows

26. Arrows

28. And (5) cooling liquid.

Claims

1. A method for manufacturing a stator, comprising: providing a stator slice group comprising stator slices, wherein the stator slice group comprises stator slices, each groove is provided with an open groove inlet, a closed groove bottom and opposite side surfaces, the side surfaces extend between the groove inlet and the groove bottom, and the size of the groove inlet is narrower than the distance between the opposite side surfaces; lining the recess with a given nonwoven material such that the given nonwoven material is adjacent to the closed recess bottom and the sides, the given nonwoven material increasing in volume when impregnated with a given cooling liquid; disposing conductor bars in the grooves of the stator slice groups such that each conductor bar faces a given nonwoven material adjacent to a side of the groove; folding the end sections of the nonwoven material over each other and over the conductor bars between the conductor bars and the open groove inlets and at positions within the open groove inlets such that the conductor bars are surrounded by the nonwoven material which increases in volume when impregnated with a given cooling liquid; and placing the groove in fluid communication with the given coolant such that the nonwoven material is impregnated with the coolant and the volume is sufficiently increased to secure the conductor bar in the groove.

2. The method of claim 1, further comprising: a pressure difference is applied to the nonwoven material impregnated with the cooling liquid in order to cool the conductor bars directly with the cooling liquid.